‘Guanajuato’, the 80km stage that is scheduled to twist through the sierra of Mexico’s Leon region on Sunday morning, will be the longest seen on an FIA WRC round since 1986, excluding Kenya’s Safari Rally.
Three decades ago, it was François Chatriot who posted the fastest time on the 83.16km stage proposed by the 1986 Tour de Corse. It took his Renault 5 Turbo/Michelin 1h7m19s to cover the run from Liamone to Suaricchio at an average speed of 74.12kph, making it the slowest test of the event.
In recent years, Rally Mexico has developed a habit of organising marathon stages and the maze of dirt trails that criss-crosses the Sierra de Lobos effectively provides its organisers with an almost infinite choice of configurations. The 2015 event included a 55.82km stage that was won by Mads Ostberg (Citroën/Michelin).
This year’s longest test (‘Guanajuato’, SS20, Sunday morning) will start in Chichimequilas, on the plain between Leon and Silao, before doing a near-complete loop of Leon to finish near El Zauco. It promises to be huge test for the crews, their cars and their tyres.
For the former, it will mean spending something like 50 minutes fighting against the clock in a cramped, sweltering and dusty cockpit, while the high altitudes visited by the test will deprive the 1,600cc turbocharge engines of a big chunk of their power, not to mention the need to keep a close eye on the fuel gauge.
Rally Mexico’s stages aren’t reputed for being excessively hard-wearing for tyres but certain portions of Guanajuato will already have been used earlier in the event, which means the loose top coating will have been swept clean to reveal a more aggressive, stone-strewn base. The drivers will consequently need to manage their tyre pressures in order to optimise the potential of their Michelin LTX Force tyres over the full distance.
The stage will be a big test of the longevity and consistency of the LTX Force H4/S4 (used by WRC crews) and the new LTX Force H91/S81 (WRC2 crews), and Michelin Motorsport’s engineers are keen to see how these tyres stand up to the punishment.
It is exactly this sort of challenge that justifies Michelin’s involvement in motorsport since it aids the development of technologies and solutions that will go on to benefit road-going versions of the brand’s LTX Force SUV and pick-up tyre.
Story by: Best-of-rally-live